perilous

1 of 2

adjective

per·​il·​ous ˈper-ə-ləs 

ˈpe-rə-

: full of or involving peril

a perilous journey

perilously adverb

perilousness noun

perilousness

2 of 2

noun

per·​il·​ous·​ness

plural -es

: the quality or state of being perilous

Synonyms of perilous

Adjective

• dangerous
• hazardous
• risky
• serious

Choose the Right Synonym for perilous

dangerous, hazardous, precarious, perilous, risky mean bringing or involving the chance of loss or injury.

dangerous applies to something that may cause harm or loss unless dealt with carefully.

soldiers on a dangerous mission

hazardous implies great and continuous risk of harm or failure.

claims that smoking is hazardous to your health

precarious suggests both insecurity and uncertainty.

earned a precarious living by gambling

perilous strongly implies the immediacy of danger.

perilous mountain roads

risky often applies to a known and accepted danger.

shied away from risky investments

Examples of perilous in a Sentence

Adjective

a perilous journey across the mountains

a perilous journey through hostile territory

Recent Examples on the Web

Adjective

Understanding the gravity of a red flag warning and adhering to these precautions is paramount in averting wildfires during these perilous conditions. —Ca Weather Bot, Sacbee.com, 19 June 2026

These currents vary in speed and can swiftly become perilous for anyone venturing into the surf. —Nc Weather Bot, Charlotte Observer, 18 June 2026

The war has also shattered transportation, turning journeys between cities that once took hours into perilous trips lasting days. —ABC News, 17 June 2026

Two college students in California died after being swept into the Pacific Ocean by rising tides and powerful surf while apparently napping near a popular but perilous beach access point, according to authorities. —Stephen Sorace, FOXNews.com, 16 June 2026

Word History

Etymology

Adjective

Middle English perilous, perelous, borrowed from Anglo-French perilleus, perillous, going back to Latin perīculōsus, from perīculum "test, risk, peril entry 1" + -ōsus -ous

First Known Use

Adjective

14th century, in the meaning defined above

Rhymes for perilous

• carolus
• garrulous
• querulous
• puberulous

Kids Definition

perilous

adjective

per·​il·​ous ˈper-ə-ləs 

: full of or involving peril

perilously adverb

perilousness noun